The present invention relates to an optical element and an eyeglass lens having a so-called reflection preventing layer (antireflection layer).
It is well known that generally, ultraviolet rays exhibit strong chemical action, and occasionally degrade the durability of various substances or elements and functions associated with them.
Further, ultraviolet sun rays, which reach the surface of the Earth's surface after have been transmitted through the atmosphere, are mainly divided into deep ultraviolet rays termed “UV-B”, having a wavelength in the region of from 280 to 315 nm, and near ultraviolet rays termed “UV-A”, having a wavelength in the region of from 315 to 400 nm. It is noted that these ultraviolet rays exhibit high potential of injury to human eyes.
At present, widely employed as a means to minimize the entrance of these ultraviolet rays into the interior of human eyes are sunglasses (including eyeglasses) due to the ease of use.
Further, many recent eyeglass lenses, other than sunglasses, comprise UV absorbers in the lens itself and are subjected to UV absorbing coating.
By utilizing such lenses for corrective eyeglasses, it is possible to shield from or minimize ultraviolet rays which come from the line of sight. Recently, however, it has been verified that ultraviolet rays which come from a direction other than in the line of sight such as, for example, those which are reflected from the face surface, reflected from the back surface of the lens, and the like, result in much more injurious effects to human eyes than have been expected.